A storage apparatus provides data storage areas for applications running on a host computer (hereinafter, a “host”) such as a server computer. The storage apparatus generally includes a large number of physical storage media and a storage controller configured to organize logical storage areas from the physical storage areas held by the physical storage media and to control data input-output processing between the logical storage areas and the host.
Hard Disk Drives (hereinafter, “HDDs”), for example, can be used as the physical storage media. In order to enhance the reliability of stored data, the storage apparatus generally employs a RAID (Redundant Arrays of Independent (or Inexpensive) Disks) method which provides redundant logical storage areas by commonly using a plurality of HDDs.
The storage controller of the storage apparatus accommodates a plurality of circuit boards to implement data input/output processing. The circuit boards include micro-processors for executing various control programs, memories for storing various data and programs, various communication interfaces each providing a function of communication with an external network or the like, power supplies for supplying power to units in the storage controller, and the like. On one hand, recent expansion of cloud computing technology, in particular, has been inducing growing demands for increase of a data storage capacity of a storage apparatus, advanced data input/output processing, and the like. To meet the demands, high-density packaging of circuit components on the circuit board, increase in the number of accommodated circuit boards, employment of a high-speed microprocessor, and the like have been promoted. Accordingly, heat generated by the circuit boards accommodated in the storage controller tends to increase more and more. On the other hand, a strong demand for downsizing of the storage apparatus leads to another strong demand for a configuration for more effective cooling of the circuit boards and components thereof in the storage apparatus with high-density packaging.
From such a viewpoint, for example, PTL 1 proposes a configuration in which cooling fans are arranged to efficiently cool circuit boards equipped with processors and memories which generate a large amount of heat. In addition, PTL 2 discloses a regulating grating for enhancing cooling efficiency of cooling fans.